Tolerability of NGX-4010, a capsaicin 8% patch for peripheral neuropathic pain

Background/purpose: NGX-4010 (QUTENZA(™); NeurogesX Inc, San Mateo, CA), a capsaicin 8% dermal patch, is licensed in the European Union for the treatment of peripheral neuropathic pain (PNP) in nondiabetic adults and in the United States for the treatment of neuropathic pain associated with postherpetic neuralgia (PHN). While NGX-4010 treatment is associated with a low risk of systemic adverse events, patch application-related pain is common and may be managed with local cooling and/or oral analgesics. This article characterizes the tolerability of NGX-4010 and will help to guide any pain management.

Methods: This integrated analysis of tolerability data collected from the NGX-4010 clinical study program included 1696 patients with PNP. Patch application-related pain on the treatment day was captured as Numeric Pain Rating Scale (NPRS) "pain now" scores while "average pain for the past 24 hours" NPRS scores were analyzed for 7 days following treatment. Other tolerability assessments included the percentage of patients completing ≥90% of the intended treatment duration and patients using medication for patch application-related pain.

Results: The mean maximum change in "pain now" NPRS scores from pretreatment levels during and after patch application was 2.6 for all patients. This pain was transient and resolved following patch removal. Mean "average pain for the past 24 hours" NPRS scores returned to baseline by the evening of the treatment day for patients with PHN, and the evening of day 2 for patients with human immunodeficiency virus-associated distal sensory polyneuropathy or painful diabetic neuropathy. Repeated NGX-4010 applications did not affect the intensity of patch application-related pain. Almost all patients (≥98%) completed ≥90% of the full treatment duration, regardless of the number of treatments received.

Conclusion: Transient patch application-related pain with NGX-4010 can be managed with local cooling and/or oral analgesics in nearly all cases. Patient adherence to the full intended treatment duration indicated that patch application-related pain was not a barrier to NGX-4010 use.